Resonant cab signaling system.



H. D. PATTERSON.

RESONANT GAB SIGNALING SYSTEM.

' APPLICATION FILED SEPT. 28, 190B.

Patented Mar.'8,1910.

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H. D. PATTERSON. RBSONANT CAB SIGNALING SYSTEM. APPLICATION FILLED SEPT. 28, 1908.

M 5 1 9 w Patented Mar. '8, 1910. I

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H. D. PATTERSON. RESONANT GAB SIGNALING SYSTEM.

v APPLICATION FILED. SEPT. 28, 1908.

Patented Mar. 8, 1910.

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Jflfi H. 1 PATTERSON. RESONANT GAB SIGNALING SYSTEM. APPLIOATION FILED SEPT. 28, 1908.

Patented Mar. 8, 1910.

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- WITNESSES I Hum/70H J Hamid 17PM Zamm HAROLD D. PATTERSON, 01E MOUNT VERNON, NE! YORK, ASSIGNOR T0 LAUDER & PATTERSON, 0F MOUNT VERNON. NEW YORK, A COPARTNEBSHIP.

RESONANT CAB SIGNALING SYSTEM.

aerate.

' display of suitable signals and also an ac tual automatic control ofa train involving the actuation of either braking mechanism or propulsion mechanism or both. Systems involving the automatic control of "such ap paratus on a train are frequently designated cab systems". it being understood that the word cab designates any suitable part of the entire train andnot necessarlly the cab to a locomotive. although the cab to the locomotive is frequently the place for the installation of the various automatic train controlling devices in such a system;

Broadly it-is an object of this'invention to improve in general cab train controlling systems.

A further object of the invention is to provide for the operation of such a system without the employment of a traveling contact device of any kind which is constrained physically to contact with stationary or movable track contacts. in order: to effect the proper control of the operation of the system and to do away with any bodily movable track instrument arranged to cooperate with a traveling device on a train and to control the same by reason of its position. Heretofore mechanical tripping contacts and electrical contacting devices have been used and have been found to be more or less unreliable as they necessarily required the accomplishment of perfect contact notwithstanding the many times unfavorable track conditions such as accumulations of snow, ice, rust, etc. which hindered the Specification of ietter's Patent.

movement of mechanical parts, or prevented '-I electrical contact being certain.

The invention contemplates the employment or both cab and track circuits.

Another object of the invention is to provide a suitable cab circuit, including a translating device and so arranged that the COIldltlOIhOll the track circuit may govern the actuation of said translating device, while the source of energy is on the train and a transformer with a multiple-part core 1s employed-one winding in a cab circuit and the other winding in the track circuit? as the means for energizing the track circuit from the cab circuit.

I It is to be understood also that an object of this invention is to provide for the tratfic controlled actuation of the cab translating devices by means of an energizing electric Pat-tented ltltar. d, llWl Ht. Application filed September 28;;9021. Serial No. 455.1l30.

circuit, the flow of current through which to control the translating devices is not established or discontinued in response to varying traffic conditions but which current How has its character or condition altered in accordance with traffic conditions to efiect the proper actuation of the trans lating device or devices. In connection with this feature it is to be understood that a change in the power factor of the alternating current employed in said circuit described is one of the changes in character or condition of the current flow contemplated and suflicient to efl'ect the desired traflic controlled actuation of the translating devices. To this end it has been found that the combination with a cab circuit of by the train and so as to reduce its air gap.

To maintain the safety condition for the current fl'ow in said translating device the effect of the said reduced reluctance may be oflset by causing said magnetic circuit to dissipate an equivalent amount of electric energy. This may be done by providing the equivalent of a short circuited winding for the core at the track. To accomplish this a winding may be provideifor the track core and suitable means be provided for causing it to be substantially short circuited .or o en circuited according to the efiect desireu. To accomplish the substantial short circuit it is preferable to provide a resonant posite reactance factors, namely,-an mductance and a condenser suitably proportioned for the purpose according to the frequency of the alternating current employed and so positioned that even grounded line wires cannot establish a false short circuit because either the condenser or the inductance alone would be in the circuit through the grounds to choke down the energy consumption for the circuit. With such a resonant circuit substantially an open circuit is created by shunting out either the inductance or the condenser. The accomplishment of this is contemplated to be effected by danger traflic condition such as the presence of a train in a block, while an actually open circuit would be effected by the danger condition caused by the breaking of a line wire. Thus the system is one in which all error is on the side of safety, which is an object of the invention.

Further objects of the invention are to provide proper apparatus and cooperating circuits in the cab, as will be set forth more at length in the following description and accompanying claims.

The above and still further objects of the invention will likewise be apparent from the following description and drawings which form part of this application, in which like characters designate corresponding parts, and in which Fi circuits and apparatus, in their re ation to the track; Fig. 2 is a diagram indicating a modification of part of the circuits shown in Fig. 1; Fig. 3 is a, diagram corres 0nding to that of Fig. 1 but showing a mo ification for receiving home actuations and not home and distant actuations; Fig. 4 is a diagram showing a modification'of the connections of a condenser for the cab circuits; Fig. 5 is a diagram indicatin one embodiment of a suitable track circuit for the system; Fig. 6 is a diagram of the modified embodiment of a suitable track circuit for the system; Fig. 7 is a modified embodiment of suitable track circuits for the system involving track relays; Fig. 8 is also an embodiment of track circuits showing another modification involving track relays; Fig. 9 is an embodiment of still another modification of suitable track circuits for the system and involving track relays; Fig. 10 is still another embodiment of track'circuits suitable for the system involving track relays and independent sources of energy for certain track circuits. Referring now more in detail to the draw- W ings a description will first be given of the apparatus and circuits for the installation the cab. Cab apparatua l indicates a suitable independent sourceof electrical energy shown gure 1 is a diagram illustratin the cab in the form of an alternating current generator drix en by a source of mechanical power 2 which may be an electric motor, as indi cated, or any suitable source of power.

G, R,and Y indicate suitable translating devices and, as shown, respectively, greensaftey, reddanger, and yellow-caution, indicating lamps. 3 and 4 indicate part of the brake mechanlsm for the train and in the embodiment shown indicate respectively a small and a largerescape duct connecting with the airbrake system for the train.

5 and 6 indicate respectively plugs cooperating with ducts 3 and 4.

T and 8 indicate respectively cores mechanically connected with the plugs 5 and 6 and operable by the magnetic effectof the coils 9 and 10 and together with magnetic yokes 11 and 12 make up the magnetic circuits for the respective translating or train controlling devices, indicated by 13 and 14. Mechanically connected to the core 7 is a frame 15 carrying suitable insulated movable cont-actdevices 16 and 17. Mechanically connected to the core 8 is a frame 18 operatively carrying suitable insulated movable contact devices 19, 20 and 21.

22 and 23 indicate respectively push buttons for restoring circuits which will hereinafter be described.

24 and 25 indicate respectively compensating inductance coils for the restoring circuits.

26, 27, 28' and 29 indicate respectively suitable condensers which may or may not be employed in the various circuits as will hereinafter be set forth.

30 indicates the primary core of a multiple part transformer. It is shown in Fig. 1 diagrammatically in front elevation and as having a -cross section of substantially E shape and providing a plurality of downwardly projectin pole faces 31, 32 and 33. This core 30 shou d be fixed to a part of the train as to the locomotive and may be secured to any suitable part on the locomotive so that the pole faces 31, 32 and 33 are horizontal and clear the tread of the rails 34 and 35. It is to be understood that the core 30 may be constructed according to well known transformer practice, as of magnetic iron laminated if desired. This core should be of an extent longitudinal to the train sufficient to insure the proper duration of super-position relative to the home second ary or track core 36 when the train is in motion. The secondary core 36 may be posi- 'tioned at the track and should have its upwardly projecting pole faces 37 and 38 so placed as .to vertically aline with the corrcsponding pole faces-31 and 32 of the core 30 and they may preferably be positioned be- 38 and 31, 32, has been found satisfactory. The core 36 may of course be made in accordance with well known transformer praci tlce and corresponds 111 many respects with core 30. Its longitudinal extent bein dej termined by the longitudinal extent of core 3 30. speed conditions, etc. The pole faces '32 i and 33 are designed to cotiperate with a secmay be similar only placed in different lateral positions at the track, as indicated.

proportionate change in the condition of the current flowing through the translating device 9 than what would result if no condenser were present.

The home cab circuit may be traced as follows :generator 1, wire 44, wire 52, condenser 28, coil 42, wire 53, front contact 54. movable contact 21, wire 55, wire 56, coil 10, wire 57, wire 51, back to generator 1. The condensers 27 and 28 are shown similarly related to this circuitand for similar purposes as are the condensers 26 and 29 of the distant cab circuit. It is also to be understood that a condenser 58 may be con- Q nected across coil 42, as indicated in Fig. 2,

42 indicates the home primary winding for core 30 while 43 indicates the distant lamp G is normally lighted and the caution and danger lamps 1 and R are normallv unlighted. In the embodiment shown. the small exit tube 3 and the larger exit tube 4 if desired. This circuit has flowing in it normal current of such condition and character as to energize translating device 14 causing the part. 6 to close large escape tube 4 and to hold the circuit controlling mech- The safety I anism in the position shown. The normal energizing circuit for safety lamp G may be traced as follows :generator 1, wire 44, wire 59, movable contact 20, front contact 60, wire 61, movable contact 16, front conare held closed by the plugs 5 and 6. the

translating devices 13 and 14 being operatively energized.

The distant cab circuit may be traced as follows :generator 1, wire 44, coil 43, wire .45, condenser 29, wire 46, front contact 4?,

movable contact 17, wire 48. movable contact- 19, front contact49, wire 50, coil 9, wire 51. back to generator 1. This circuit normally carries suflicient current of a suitable condition or character normally to energize distant translating device 13 which 3 comprises two parts: one part 5 normally i i third IZlll' 72 18 indicated and it is to be closing the small escape tube 3 and another 40 ()bviously. if desired. thesetwo parts 5 and 15 might. be operated by either a plurality part 15 being a circuit controlling device.

of separate cores 7 of the single core 7 as shown and as descrlbed. Inasmuch as the 1 energizing current for coil 9 normally flows, it is sometimes desirable to distort the power factor of the circuit so that a useless waste of power is not occasioned. The coils 43 and 9 of this circuit obviously present a certain amount of inductance in the circuit 5 and it has been found to be desirable sometimes to eftectthe distortion of the power factor by means of condensers.

To satisfy different conditions a condenser 29 may be 5 connected in series in the circuit as is the condenser 29 or the condenser 26 ma be 5 "across the terminals of coil 43 as shown in 59 Fig. 2 or various combinations of condensers connected in various ways may be employed. I The use of a condenser in series with a coil such as 43 is important because a certain change, efiected 'by'trafic control, in

the inductance of coil 43, causes a greater tact 62, wire 63, lamp G, wire 64, wire 65,

wire 51, back to generator 1. The normally understood that the system described in this application might be used in connection with electric railways of the type employing a continuous one rail return or of the type employing a continuous one rail return together with an opposite broken rail suitably bonded by well known inductance bonds and which bonds are selective agalnst the signaling current. which should preferably be of different character as to phase and frequency from the character-of the propulsion current which may traverse the said inductance bonds against comparatively little re-actance.

In Fig 3 there is illustrated diagrammatically an installation of apparatus and circuits for the cab in which only a home cab circuit is shown and in which the primary core of the transformer has but a single pair of poles31 and and a single coil 42. 1 In this figure the home cab. circuit may be traced as follows :-generator 1, wire 44, condenser 73. wire 74, coil 42, wire 50, coil 9, wire 51, backto generator 1. This circuit normally ener gizes controlling device 13 which in this embodiment operates only the circuit trans lamp G and back to generator 1.

' contacts 19 and 49 will be present in the disflow of the alternating current in traflic rails.

previously described, and having upwardly trolling device may be treated as folondary coil or winding 94 of a suitable num- &

lating device 15. A separate controlling device is shown, indicated by 7 5, and controlling a propulsion circuit by means of switch 1 76, it being understood of course, that the switch 7 6 may control the power circuit for the propulsion current or any other suitable I part of the propulsion mechanism. l

The normally energized circuit for signal i for normally energizing conlows :generator 1, wire 44, condenser 73, wire 74, w1re77, movable contact 16, front ,contact 62, wire 63, thence branching into two parallel pathsone, wire 78, coil 79, wire to point 81; the other. wire 82, I lamp G, wires 83 and 84 to point 81; thence 2 together over wires 85 and 51, back to generator 1. l The normally open circuit for dangr i lamp B, may be traced as follows ;generator 1, wire 44, condensed 73, wire 74, wire 7 7 movable contact 16. back contact 66, wire 67, danger lamp R, wires 68, 84, 85 and 51,

Fig. 4 shows a condenser 87 connected 1 across the terminals of generator 1 and may be employed at willQin the other figures and .as will be understood.

23, inductance 25 (which is substantially equal to that of coil 42), wire 89, back contact 90, movable contact 21, wire 55, wire 56, coil 10, wire 57, wire 51, back to generator 1. The distant restoring circuit may be traced 7 as follows :-generator 1, wire 44, wire 91, push button 22, inductance 24 (which may be substantially equal toft-hat of coil 43), wire 92, back contact 93, movable contact 17, 3 wire 48, movable contact 19, front contact i 49, wire 50, coil 9, wire 51, back to generator 1. The two restoring circuits above are respectively normally open between contacts 90, 21 and 93, 17. A break between,

tant restoring circuit in case the home controlling translatingdevice or relay 14is deenergized.

Track czrcuzts.The applicant has taken advantage of the inherent reactance to the It has been found that this reactance is considerable for the length of the ordinary block section due to the magnetic nature of the rails. In many signaling systems this reactance in a rail circuit has been disadvantageous. 1 On the other hand in the present system it is utilized in eifectingtrain control.

The embodiment of one'successful track circuit is shown diagrammatically in Fig. 5. In this figure, 36 is the home'secondary core,

presented pole faces 37 and 38, and its secber of turns but of low ohmic iesistance. This core may be located at the track any suitable distance in advance of the block l'section A- to be tested. Farther from the block section A is located the distant secondary core 39, with a winding 96 the same as 94. The longitudinal distance between cores 36 and 39 may be determined to suit desired conditions and also the location of z the home secondary core 36 in advance of the block section.

' The distant track circuit may be traced as follows :coil 96, wire 95, coil 94, wire 97, condenser 98, wire 99, traflic rail 100, cross bond 101, continuous track rail102, wire 103 back to coil 96. When the home :test is being made the home track circuit is traced in the same manner except that the coil 94 serves as a source of energy instead of the coil 96. It is 'to be understood in this embodiment that the cross bondlOl may be of the inductance type as indicated and of any suitable construction or of the conductance type if desired. The condenser 98 is proportioned so as to nullify the combined inductance due to i one of the coils 94 or 96, the number of turns and the inductances in which are equal; the inductance of the track rails for the circuit; and the inductance of the bond 101. There results therefore a resonant circuit. The coil 94 or the coil 96, when it is serving as the secondary of the transformer and consequently is the source of alternating current for the track circuit is not considered in the calculation of inductance for the track circuit for obvious reasons.

A modified embodiment is illustrated in Fig. 6. The secondary cores and coils may be the same and located the same as in Fig. 5. Additional inductance, however, may be inserted in the track circults, as between the coil 94 and the trafiic rail 100. It is indishown in Flg. 5. For some purposes, how- 1 ever, its location'at the far end of the block section is desired, especially in case of long blocks when thefall of the potential due to the impedance through the rails and leakage across front one to the other is considerable.

It is to be understood of course, that the installation illustrated in Figs. 5 and 6 for block sections A may be repeated indefinitely for succeeding block sections B, etc., as desired.

. Another embodiment of track circuits is illustrated in'Fig. 7. In this embodiment a relay is employed in connection with the track circuits. In this installation a relay device is indicated by 105. The embodiment is-merely illustrative and it is to be undercoil 96.

stood that the relay device may be of any suitable character capable of responding to the current in the track circuit and of controlling its relay circuit, as will hereinafter be apparent. This relay device may have one or more coils, at least one of which is energized the track circuit. For section A two secondary cores 39 and 36 are pro- 'vided just as in the installation shown in may be traced as followsz-winding 106,

wire 95, winding 107, wire 97, rail section 100, wire 108, one coilof relay 105, wire 109, rail 102 wire 110, back to winding 106. The home track circuit for this section is the same as the distant track circuit, except that winding 107 serves as the source 1 c I should be understood that, although but one The distant track relay circuit for section of electrical energy.

A. may be traced as follows :-coil 96, wire 111, coil 94, wire 112, condenser 113, wire 114, circuit closer 115, front contact 116, wire 117, inductance 118, wire 119, back to The home track relay circuitis the same only coil 94 is the source, not coil 96. If desired, the inductance 118 may be omitted from this circuit. The condenser 113 is proportionedso as to be equal and opposite to the entire inductance of the circuit with the exception of the mutual inductance due to the several turns of one of the coils, either 94 or 96. A portion of a similar installation is shown for section B and shows how it may be repeated indefinitely for any desired number of sections.

A modification of the installation shown in Fig. 7 is shown in Fig. 8, except that but a single secondary core 36 is provided for each A block section, thus insuring merely a home test for each section. This core is provided,

In Fig. 9 a similar system but slightly modified is illustrated. In this system the track relay circuit does not include the rail 102. All other circuits are the same as described for the embodiment shown in Fig. 8. Therefore the track relay circuit alone will be traced as follows. the tracing being applicable for the installations in both sections j A and B :-coil 94, wire 110, condenser 113, wire 114, circuit closer 115, front contact 116,

f wire 11?, inductance 118, wire 119. back to 107 respectively, in addition to the coil 94. The condenser 115 for this circuit is proportioned so as to be equal and opposite to the entire inductance of the circuit with the exception of the inductance due to windin 94. In Flg. 10 there is illustrated still a. different type of installation for the trackcircuits. In this installation, the track circuit for each section is provided with its own independent source of electro-motive force. It

complete installation for one block section A is illustrated and apparatus for block sec- -tion B, the installation may be repeated indefinitely for as many sections as desired throughout the railway system. Tn this installation the track circuit is also normally closed but, in addition, normally is energized and may be traced as follows :-source 120, wire, 121, rail section 100, wire 122, relay 123,

wire 124, rail 102, wire 125, back to source 120. The distant track relay circuitmay be traced as follows :coil 96, wire 126, resistance 12?, wire 128, circuit closer 129, front contact 130, wire131, back to coil 96. The home track relay circuit may be traced as tollows:-coil 94, wire 132, resistance 133, wire 134, front contact 135, circuit closer 136, wire 13?, back to coil 94. These two track.

F relay circuits are normally closed as shown.

It is to be understood that the cores 36 and 39 may be the same as those described in connection with Figs. 5, 6 and 7, and in fact as is the same core shown in Fig. 7 with one winding 94, and also with an independently 1 connected winding 106. The installation is shown complete for two block sections A; and B, and may be repeated indefinitely. g

The track circuit for either section may be traced as followsz-winding 106, wire 97,'

rail 100, wire 108, one coil of relay 105, wire 111, rail 102, wire 110, back to winding 106. The track relay circuit for this installation may be traced as follows :coil 94, wire 110, rail 102, wire 111, wire 112, condenser 113, wire 114, circuit closer 115, front contact 116, wire 117, inductance 118, wire 119, back to coil 94. In this circuit the condenser 113, is also proportioned so as to be equal and opposite to the inductance of the entire circuit with the exception of the inductance due to winding 94. In this case the inductance due to a section of rail 102, must becalculated.

all other parts similarly numbered are the same.

0perati0n.The cab apparatus and circuits are shown in normal condition, in which showing the relays 13 and 14 are 0p eratively energized and the escape ducts 3 and 4 from the air brake system are both closed and the safety lamp G is lighted.

The direction of movement for the train 7 and train installation is from left to right in Figs. 5 to 10 inclusive and should be imagined as being vertically toward the observer, in the diagramsiof Figs. 1, 2 and 3. Under normal conditions the reluctance of the magnetic circuits for coils 42 and 43 is largely due to the large air gap between poles 31, 32, and 32, 33, respectively. Consequently quite a considerable magnetizing currentmust' flow through coils 42 and 43.

This magnetizing current flowing is sufii cient operatively to energize the relay devices 13 and 14 in the circuits previouslytraced. As the train advances the core 30 will pass first over the secondary or distant core 39, the pole faces 32 and 33 alining respectively with pole faces 40 and 41. When the primary and secondary cores are superposed they cotiperate and the secondary core 39 will materially reduce the reluctance of the magnetic circuit for primary coil)43 and reduce the necessary energizing current for this coil, provided no other conditions exist. Other conditions do exist, however, namely, the secondary core 39 is provided with a secondar winding 96. The magnetic lines traversing core 39 induce an electric potential in the winding 96 and cause a flow of current in the distant track circuit. As previously described, when the track circuit is in normal condition, it is resonant. The flow of current through the secondary coil 96 is therefore comparatively large as it is limited merely by the ohmic resistance of the track circuit. In order to supply this large flow of current in the secondary coil, as much or more magnetizing energy must flow in the primary winding 43 about primary core 30 and in coil 9 as or than normally flows. Thus when the track circuit is clear, the distant cab circuit, energizing relay 13 is maintained operative for relay 13. Should a train be present in block section A, so as to bridge across from rail section '100 to rail 102, the wheels and axles of this train will shunt out a material portion of the inductance of the track circuit, when the track circuit is as illustrated in Fig. 5 or a material portion of the capacity of the track circuit when the same is as shown in Fig. 6. The unbalanced capacity or inductance remaining in the track circuit will then alter the condition of the current flowing through the secondary coil 96. In the embodiments illustrated its power factor will materially be shifted so that the magnetizing energy fiowingthrough coil 43 will be reduced to such an extent that the same energy current which flows also through coil 9 or relay 13 will be insuflicient operatively to energize this relay; the plug 5 will be removed from the exit duct 3 which will allow the gradual escape of air from the air brake train line and gradually apply the air brakes to the train to check its speed; movable contact 16 will break connection with front.contact 62; and make connection with back contact 66; and movable contact 17 will break connection with front contact 47 and make contact with back contact 93.- The distant cab circuit for coil 9 is therefore ermanently broken between oints 47 and 1 The circuit for safety amp G is broken between 62 and 16, and the circuit for caution lamp Y is closed between pointslh and 66 so as to display the necessary caution indication.

'duced so that home relay The train then proceeds cautiously ,until home secondary core 36 is reached. After receiving the caution indication, the circuits may be restored to normal conditions by the engineer by pushing the button 22 which ,..independently energizes the distant cab circuit, previously traced, by means of the distant restoring circuit previously traced, it being understood that the contacts are so arranged that this restoration may be accomplished.

Upon reaching the home secondary core 36, the current through primary winding 42 is controlled in the same manner as was the current for primary winding 43, previously described. If the track circult is normal and substantially resonant, the home cab circuit will be kept normal and the train may proceed. However, should a train be occupying block section A, the current flowing through primary winding .42 will be re- 14 is no longer energized, the plug 6 wil open exit duct 4 which permits the escape of air from the air brake line sufliciently rapidly to bring the train to a quick stop. At the same time movable contacts 19, 20 and 21 break connection with front contacts 49, 60 and '54 respectively, and the movable contacts 20 and 21 make connection with back contacts 69 and respectively. The break between contacts 49 and 19 opens the circuit for distant relay 13, which assumes its deencrgized position, previously described, opening the exit duct 3 to facilitate the exhaust of air pressure from the train line. The caution circuit, one break in which was thereupon closed by contact 16 making connection with back contact 66, is,however, maintained open by the break between front contact 60 and movable contact 20. -Movable contact 20 contacting with back contact 69 closes the circuit for and energizes danger lamp A permanentbreak in relay l4s own clrcult occurs between movable contact 21 and front contact 54, while one break in the home restoring circuit is closedbetyveen contacts 21 and 90. The train is then brou ht to a full stop and cannot proceed until t e home cab circuit has been restored to normal conditions. This may be accomplished by operating the push button 23, which completes the home restoring circuit previously traced and restores the relay device 14 to normal conditions. The push button 23 may be mounted in any suitable locality. The distant circuit may then be restored by pushing push button 22 which operation has previously been described. The train may then proceed cautiously until a safety indication is re- .ceived.

It is to be understood that this system of controlling the cab apparatus illustrated 1s equally applicable to controlhn cab apparatus and circuits provided wit modified aanaaa apparatus and with additional cautionary apparatus insuring the cautious advance of the train.

circuits as illustrated in Fig. '2', the operation of my system is similar to thatdescribed but subject to modified steps. either the core 39 or thecore 36 1s magnet ized according to whether the one or the other is superposed by traveling primary cpre 30, so that either the coil 106 or 107 of current in the cab circuit previously de scribed. However, should a train be pres- 5 cut in the block section or should the circuit When used in connection with the track be accidentally broken, the relay 105 will not beenergized and the interposition of f the core 36 with the open circuited winding ltn particular,

so as to decrease the "reluctance of the magnetic circuit for the primary winding 12 serves as a source of electro-motive force for the track circuit, completing the same through-the relay 105 if the block is clear. The relay 105 is then operatively energized to cause circuit closer 115 to contact with front contact 116 completing a resonant circuit through coils 94:. and 96, similar to the other resonant circuits previously described. The flow of current through this resonant circuit will be sufliciently large'to cause a normal flow of current through the testing primary winding about core 30, that is through winding 43 or 42 and the corre sponding cab relay device 13 or 1 1 will remain operatively energized. In case, however, a train is present in section A, its wheels and axles will shunt out relay 105 preventing circuit closer 115 from closing the track relay circuit previously traced. The necessary flow through the energizing primary winding either 13 or 42 will'consequent-1y be insuflicient operatively to energize the corresponding cab relay 13 or 11, and the consequent caution or danger indication or train control, as previously described, will result. ltn the track installation shown in Fig. 7, the number of turns in coils 94. and 96 greatly exceeds thea'n'umber of turns of coils 106 and The operation of the system in connection with a track installation as shown in Fig. 8 .is illustrative of its operation when merely home tests are capable. ltn this installation merely the home secondary cores 36 are illustrated The secondary winding 94 is present but has a few coils indicated. by 106 separately connected to serve as the source of energy for the track circuit which has previously been traced. The operation ofthe system in response to this track installation is fundamentally the same as that described in connection with Fig. 7. Reference should be had, however, particularly to the cab installation illustrated in Fig. 3, in which the primary or traveling core 30 has buta single winding, that is the home winding 12. When the core 30 passes over core 36, core 36 is magnetized so as to set up a flow of current in the track circuit, pre viously traced, and to energize the relay 105 if the block section A is clear. Relay 105 causes circuit closer 115 to close the resonant track relay circuit previously described, which in turn causes a normal flow 107 respectively.

will cause a decrease in the How of current. in the cab circuit so that relay 13 will not be opera tively energized. Then movable con tact 16 will break connection with front contact 62. thereby cutting out the circuit for the safety lamp and will make connection with back contact 66 to close the danger circuit. The breaking of connection with front contact 62 also de'nergizes train controlling device to eiiect the opening of switch 76. The opening of switch 76 may be utilized to cut off the propulsion current from the propulsion motors or to cut oil the supply of steam to the cylinders of the locomotive by means of a suitable relay apparatus all well known in the art. Movable contact 16 will make connection with back contact 66 and close the circuit for danger lamp R to give a danger indication. This cab installation may be restored to normal position by a restoring circuit similar to' that shown and described in connection with Fig. 1. This operation will, of course, be repeated indefinitely when each block section of the system is tested.

In Fig. 9 is illustrated a system of track circuits and apparatus substantially the same as was shown in Fig. 8. The only difi'erence is in that an independent conductor 110: is employed in the track relay circuit instead ofusing the continuous rail 102 for a conductor. The operation of this installation will therefore be understood from the description of the operation of the installation shown in Fig. 8, as it is the same.

At this point it may be well to call attention to the arrangement of the track relay circuits illustrated in Figs. 7, 8, 9. It is to be noted that the condenser 113 is inserted in one conductor leading to the circuit closer 115, while the inductance is inserted in the other conductor leading to circuit closer 115. By this arrangement, should either one or the other of these conductors be grounded or, for that matter, should an accidental crossing occur, it would be practically im possible so to efl'ect a resonant conditlon for the circuit and thereby make possible the giving of a false safety indication when tested. To this end it maybe preferable to locate the condenser 113 adjacent to the circuit controllingdevice 115 and the inductance 118 adjacent to the secondary core 36. In general it is the object so to position the condenser and inductance relatively to the circuit as to prevent the bringlng about of a resonant condition from an accibe desired.

In Fig. .the track circuit previously traced is not merely normally closed but is also normally energized by an independent source 120. This'circuit maintains the track relay 12-3 normally energized and this relay 7 normally holds both the home and the distant relay track circuits closed. It will be obvious to those skilled in the art that this track circuit is similar to the normally closed track circuit used frequently for semaphore block signaling and in fact the track relay of such a semaphore system might serve when provided with suitable contacts illustrated for the relay 123, or in fact suitable circuit closers might be operated directly by the semaphore arm to accomplish the functions of the circuit closers of relay 123. This is the condition which exists when the block section is clear, that is unoccupied bya train and the rail circuit unbroken. The resistances 127 and 133 in the distant and home relay circuits are merely sufficient to prevent an excessive current. flow in the secondary coils 96 and 94, when their respective cores 39 and 36 are superposed by andcooperate with the traveling primary core 30. The same result may be obtained by properly designing the secondary coils 96 and 94 to give a smaller electromotive force. Obviously, when a distant test is made by means of distant secondary core 39 and distant. secondary coil 96, a substantially short circuited secondary winding is met with and the consequent flow of energy therethrough will be suiiiciently great to maintain the normal value of the flow of energy through the distant relay 13 at the cab and maintain a safety indication. The same conditions as to core 36 and coil 94 will be met with upon making the home test of block section A. However, should block section A be occupied by a train or should the rail circuit be broken, the relay 123 will be denergized and the circuit closers 129 and 136 will open the distant and the home track relay circuits respectively. Consequently, when a test of each of these circuits is made, there will be no flow of energy therein and the cooperative interposition of either of the distant secondary core 39 or thehome secondary core 36 in the corresponding magnetic circuits for the distant and the home primary coils 43 and 42 would so decrease the reluctance of these magnetic circuits as to reduce the flow of energy in the distant and home cab circuits to as to prevent the distant and home relays 13 and 14 being operatively energized. This would cause the necessary train control as previously described. It is, of course, to be understood that either the home or the distant track relay circuits shown in Fig. 10 could be rendered normally resonant circuits.

The result of an accidental break in the rail circuit, shown in Figs. 5 and 6, is an open circuit for the secondary coils of cores 39 and 36, and consequently would occasion the display of a danger indication in the cab, regardless of whether or not the section having the broken rail was occupied by a train.

It will be understood from the nature of the apparatus described, that it is desirable that the generator 1 on the cab should supply a. constant potential and, of course, be capable of supplying current to the various circuits which it energizes in accordance with the demand putupon it. As a certain amount of current must constantly flow in the cab circuits and must constantly magnetize the primary core 30 and operatively energize the cab translating devices 13 and 14, it is desirable that as little power be consumed, as possible. To this end various manners of connecting condensers in the cab circuits have been illustrated for the purpose of distorting the power factor therein. It is, of course, to be understood that in practice all the condensers shown, as for instance in Fig. 1, would not necessarily be used or needed, and need not be connected, necessarily, as shown, but with one or more of the other modified manners of connecting them and as shown by Figs. 2, 3 and 4, might be used as described alone or in combination. Furthermore, although the two coils 42 and 43 in the cab installation are shown wound on a single primary core 30, in which pole 32 is common. to the magnetic circuits of. both coils 42 and 43, it is to be understood that this common pole construction is merely for the sake of economy in material. Fi 3 shows the form of core having two po es for a single rimary winding independent of the poles or the core of any other winding. It is also to be understood that the number of turns in the secondary coils at the track may have any dc sired ratio to the number of turns in their cooperative primary coils. Thus the two part transformer may either ste down or step up, as described, the potentia of enerator 1 in its energization of the trac circuits.-

This description is not supposed to be a specific description of the various apparatus suitable in the system, as it is to be understood that any suitable apparatus such as translating devices (which term is used in its broad sense), cores, bonds, etc. may be employed. The translating devices 13 and 14 m the cab installation should be such as to be properly energized by a certain than suficient to insure satisfactory operation of devices such as 13 and 14. It is also to be understood that the track relay devices may be of any desirable and suitable kind known in the art. In cases where sensitive relays are desirable, relays of the type de scribed in 'Struble patent 863,667 or in Towsend patent-r 804,176, might be used and are contemplated. lit-Fig. 5 an inductance bond 101 is shown while in Fig. 6 a

.condenser or capacity bond 98 is shown.

Whichever kind is to be used it is to be considered in the calculation of the resonant circuit and the two types will be referred to generally by the term reactance-bond ft is also contemplated that combinations of the various circuits and devices illustrated and described other than the combinations shown would be possible and within scope of this invention.

- This a lication s cificall a lies to track circ i ts in which one or of the traction rails are divided into insulated sections, as shown by the various ti res. It is. however to be understood that the broad features of the system, apply equally well to track circuits in which both of the traction rails. are continuous but which is claimed specifically in my copending application, Serial Number 455,179, filed on even date herewith.

at is claimed and what is desired to be secured by United States Letters Patent is 1. In a cab train controlling system, a source of alternatin potential carried in the cab; a train-controlling device in the cab; a train electro-magnetic device suspended over the track; a circuit including said source and said train electromagnetic device and controlling said train-controll device; a track electromagnetic device positioned in the path of the traveling field of said train electro-magnetic device; and a tramc controlled normally resonant circuit at the track closed through said trach electroma netic device d including substantial y W equal but opposite'reactance factors.

bit

2. ln a cab train controlling system, a source of .alternatin potential carried int-he cab; a train-control device in the cab; a electromagnetic device suspended over the. track; a circuit including said source mary core having a primary winding and carried, by the cab, the other part being a cooperable secondary core positioned at the track; a source of alternating current on the cab; a translating device and a condenser in the cab; a normally closed excitin circuit for said primary core including sai source, said primary winding, said condenser and said translating device and normally carrying current 0 a condition operatively to energize said translating device; a traffic control-led means operable upon said secondary core to maintain the normal value of the current for said translatlng device upon clear traffic conditions and 'when said cores are in cooperative relations, by ofisetting the consequent reduction in the reluctance of the magnetic circuit of said rimary core by causing the dissipation of e ectric energy.

i. In a cab train controlling system, a twopart transformer core, one part being a pri mary core, having a primary winding and carried by the cab, the other part being a cooperable secondar core having a secondary winding and positioned at the track; a source of alternating potential in the cab; a translating device in the cab; a normally closed exciting circuit for said primary core ineluding said source", said primary winding and said translating device and normally carrying current of a condition operatively to energize said translating'device; a block section; a closed normally resonant circuit including said secondary winding and suitably proportioned inductance and capacity, said resonant circuit having such relation to the trafic rails of said block section that the presence of a train in the sections or a broken J operable secondary core having a secondary winding and positioned at the track; a source of alternating potential in the cab; a trans lat my device in the cab; a normally closed exciting circuit for said pr mary core nitw said source, sa d primary winding and id translating device and normally llhtl ltd 40 a cooperable sconda carrying current of a condition operatively to energize said translating device; a block section; a closed normally resonant track circuit including said secondary winding, 5 the opposite rails of said section and suitably proportioned capacity all in series, whereby the presence of a train in said section or a broken rail will destroy the resonant condition of said track circuit and ,con-

10 sequently reduce the possible flow of energy in said circuit.

6. In a cab traincontrblling system, a

two part transformer core, one part being a primary core having a primary windin and 5 carried by the cab, the other part being a cooperable secondary core having a second ary winding and positioned at the track; a source of alternating potential in the cab; a translatin device in the cab; a normally go closed exciting circuit for said primary core including said source, said primary winding and said translating device and normally carrying current of a condition operatively to energize said translating device; a block section including an insulated rail section;

a closed normally resonant track circuit including said secondary winding, the opposite ralls of said section, an inductance in addition to that of the rails, and suitabl pro- 0 portioned capacity all in series, whereby the presence of a train in said section or a broken rail will destroy the resonant condition of said track circuit and consequently reduce the possible flow of energy in said circuit. 4

7. In a cab train controlling system, a two-part transformer core, one part-being a primary core, havin a primary winding and carried by the ca ,the other part being core having a secondary windin and ositioned at the track; a source of a ternatmg potential in the cab; a translating device in the cab; a normally closed excitin circuit for said primary core including sai source, said primary winding and said translating device, and normally carrying current of a condition operatively to energize said translating device; a block section including an insulated rail section; a'clo'sed normally resonant track circuit in- "cluding said secondary winding, said insulated railsection, a reactance bond, and the opposite rail of said block section all in series and also including suitably proportioned 55. capacity, whereby the presence of a train in said block section or a broken rail willde- "stroy the resonant condition of said track circuit and consequently reduce the possible flow of energy in said circuit.

8. In a cab train controlling system, a "h ome and a distant two-part transformer core, one part of eachbeing a rimary core having a primary winding an carried by the cab, the other ;part of each being a coes operable secondary core'haying a secondary,

winding and positioned at the track; a source of alternating potential in the cab; a home and a distant translating device in the cab; a normally closed home cab circuit including said source, the home primary winding and the home translating deviceand a circuit breaker normally held closed a by said translating device; a normally closed distant cab circuit including said source, the distant primary winding and the distant translating device and acircuit breaker normally held closed by said translating device; both of said can circuits normally having a current flow operatively to energize the translating devices; a-track controlled means 0 comprising a circuit including said secondary winding for each of said secondary cores and for effecting traflic controlled dissipation of the electric ener and thereby modifying the cooperative e ect of said home and distant secondary cores upon the corresponding primary cores and consequently upon the operative flow of current through said homeand distant translating devices to eifect trafii'c controlled train control upon both home and distant tests; and means at the cab for restoring each of the cab circuits to normal condition independent-1y of the track circuits.

9. In a cab train controlling system, a home and a distant two-part transformer core, one part of each being a primary core having a primary winding and carried by the cab, the other part of each being a 006 erable secondary core having a secon ary winding and positioned at the track; a source of alternating potential on the cab; a home and a distant translating device in the cab; a normally closed home cab circuit including said source, the home primary winding and the home translatin device;

a normally closed distant cab circuit includ ing said source, the distant primary winding and the distant translating device, both of said cab circuits normally having a current flow operatively to energize the translating devices; a block section including an insulated rail section; a resonant track circuit including both the home and the distant secondary windings, said insulated rail section, the opposite rail of the block section and a resonating capacity, all-in series.

10. In a cab train controlling system, a home and a distant two-part transformer core, one part of each being a primary core a home and a distant translating device in the cab; a normally closed home cab circuit including said source, the home primary windin the home translating device and a circuit fireaker normally held closed by said translating device; a normally closed distant cab circuit including said source, the distantprimary winding, the distant translating device and a circuit breaker normally held closed by said translating device; both of said cab circuits normally having a current flow 'operatively to energize the translating devices; a block section including an insulated section; a resonant track circuit including both the home and the di tant secondary windings, the opposite ralls of the block section and a resonating capacity all in series: and means at the cab for restoring each of the cab circuits to normal condition independently of the track circuits.

11. In a cab train controlling system a source of substantially constant potential alternating electromotive force'in the cab a translating device in the cab having zv'bias to danger condition; a condenser in the cab; a discontinuous core of magnetic material having a primary winding and forming part of the magnetic circuit for said primary winding and carried by the cab; a closed and u a l I l D energized cab circuit. including sald source,

said translating device, saidacondenser and said primary winding, by means of which the condition of the current-inthe said translating device, due to the normal high reluctance of said discontinuous core, normally maintains it in safety condition; a stationary core of magnetic material positioned at the track in the path of the magnetic field of said discontinuous core in the cab, to reduce the reluctance of the magnetic circuit for said primary winding when said cores are in juxtaposition; and means at the track for causing the said magnetic circuit for said primary winding. under safety track con- 40 ditions, to dissipate electric energy tomaintain the safetycondition of said-translating qidevice. when said cores are juxtaposed an the reluctance of their combined magnetic circuit is consequently reduced.

12. Ina cab train-controlling system a source of substantially constant potential alternating elect'rom otiye force 'in the cab; "21 translating device in the cab haying a bias todange'r condition; a discontinuous core of i'nagnetic' nmteri'al' having a primary wind; mg"andflfoi ming a part. of theinagnetic circuit 01 said primary winding and car- "riedby thecab; a closed and energized cab ficu'cult mchidmg said source, said translating device and said primary winding, by means ofwhich the condition of the current v 'in: the said translating deyice, due to the normal high reluctance of said discontinuous core, normally malntains 1t in safety condition: one or more condensers combined track for causing the said magnetic circuit for said primary winding, under safety track conditions, to dissipate electric energy to maintain the safety condition of said translating device, when said cores are juxtaposed and the reluctance of their combined magnetic circuit. is consequently reduced.

13. In a cab train controlling system a source of substantially constant potential alternating electromotive force in the cab; a translating device in the cab having a bias to danger condition; a discontinuous core of magnetic material having a primary wind ing and forming a part of the magnetic circuit for said primary winding and carried by the cab; a closed and energized cab circuit including said source, said translating .device and sald primary winding, by means of which the condition of the current in the said translating device, due-to the normal high reluctance of said discontinuous core, normally maintains it in safety condition; one or more condensers combined with the devices of said cab circuit to offset their" for increasing said impedance when the.

track isbroken or occupied, to annul the reluctance reclucmg effectof said stationary core. in the one instance and in the otherinstance. 1 a

i to maintain 1 In. testimony ivhereof, I have signed my! name tothis specification, in the presence of two subscribing witnesses. y

J HAROLD D. PATTERSON. \Vitnesses: V J

C. E. HA USELMANN,

EnsoN B. SA'MMIS. 

